--- In firebird-support@yahoogroups.com, "Adam" <s3057043@...> wrote:

> What is the confusion?
>
> Nov 17 1858 is day 0.
> Nov 16 1858 is day -1
> Nov 15 1858 is day -2
> etc.
>
> The data definition simply tells you not to try and use dates

outside

> that range.
>
> As Ann (and others have advised), if the *null flag* is set on a
> field, the *value* stored in that field is not relevant. An
> implementation artifact causes the *value* to be set to 0 when the
> field is null.
>
> Zero and null are 2 different things. If you don't understand that,
> you should read the Firebird Null Guide on this page:
> http://www.firebirdsql.org/index.php?op=doc
>
> Older versions of Firebird were not able to pass a null to a UDF, so
> it is understandable that such UDFs would use the value stored in

the

> field ignoring the null flag. Firebird 2 supports null signals to

UDF

> calls. (See chapter 13 of release notes).
>
> So if you want your UDFs to handle NULL properly, you will need to

be

> using Firebird 2, using a version of the UDF that understands the

new

> convention (check with UDF vendor), and have the UDF declared in

your

> database to correct way (check with UDF vendor).
>
> Adam

Adam,

Thanks for your response...it makes alot more sense to me now.


Best Regards,

Jeff